Cement additives or admixtures are special chemicals which are added to a batch of cement before or during mixing to impart desired properties to the cement. The bonding strength of cement is one such property which can be augmented via the use of various additives.
The properties of a cement are also affected by its air content. For example, a high air content enhances the workability of the cement by increasing its plasticity, thus making it easier to use. However, a high air content also decreases the bonding strength of the cement. Indeed, it is common practice in the cement industry to increase a cement's bonding strength by decreasing its air content.
A need exists for additive compositions for incorporation in hydraulic cement mixes which are capable of improving a cement's bonding strength without decreasing its air content and workability.